Re: NOT LIKE much faster than LIKE? - Mailing list pgsql-performance

On Tue, Jan 10, 2006 at 02:44:47AM +0100, Andrea Arcangeli wrote:
> "cooperative" runs "WHERE kernel_version NOT LIKE '%% PREEMPT %%'", while
> "preempt" runs "WHERE kernel_version LIKE '%% PREEMPT %%'. The only difference

One thing you could do is change the like to:

WHERE position(' PREEMPT ' in kernel_version) != 0

And then create a functional index on that:

CREATE INDEX indexname ON tablename ( position(' PREEMPT ' in kernel_version) );
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Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
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